Sherlock Learns What He Likes
by wendymarlowe
Summary: Sherlock is still shaken up by his reaction to Irene Adler and her riding crop and can't figure out why. He drags John to go meet Irene, who is happy to help design an experiment which ultimately involves lots of toys, Sherlock tied naked to a bench, and John cataloging responses on a chart because Sherlock wants to be all scientific about it. It's hard to just observe, though ...
1. Chapter 1

Sherlock was working up to a good proper rant when John walked in and spoiled it. Sherlock stopped, mid-sentence, and glared.

"Where were you? I've been talking to you for half an hour."

John sighed and let the door swing closed behind him. "I was out at Tesco, Sherlock, just like I told you an hour ago. You really do carry on conversations when I'm not here?"

"Not intentionally."

"Why don't you just talk to the skull?"

"Because it doesn't know anything about penises."

That got John's attention. "Sorry, what?"

"Penises, John. I was soliciting your opinion."

John blinked. "Generally in favor, I suppose? Why?"

Sherlock made an angry slashing motion with his hand. "No, not that. About my situation."

"Right then. Better start back at the beginning, now that I'm actually present. I think I need to hear the full explanation for this." John dropped his sack of groceries on one of the kitchen chairs - the table was too full of Sherlock's laboratory apparatus to hold anything more - and came back into the living room so he could at least get comfortable in his armchair while Sherlock ranted.

"The Woman - she's the beginning of this." Sherlock dropped heavily into his own chair. "You saw it - she drugged me and hit me with her riding crop."

John nodded patiently. "Yes, I do rather remember hauling you back here and putting you to bed. What's that got to do with whether I approve of penises?"

"Nothing - I meant your medical opinion." Sherlock's eyebrows drew together. "While I was lying there on the floor, I got an erection. An _erection_, John. I don't understand - I never bother with those." He shook his head as if the thought of actually getting hard was patently absurd. "I assumed it was a side effect of whatever she drugged me with, but it won't go away and I don't know what to do."

"Sherlock, when you say it won't go away . . ."

"Not continuous, obviously, but I haven't allowed myself an erection since I was a teenager and now I get one nearly every time she texts me. Which is fourteen times today already."

"Ah." John tried to keep his best "doctor face" on. "You said you don't allow them - do you not get erections at all, or you just don't follow through?"

Sherlock shrugged. "I rarely get them, and when I do I ignore them until they go away. I've gotten it to where it usually only takes a minute or two."

"Ah," John said again, and chose his next words carefully. "You do . . . know . . . why she keeps a riding crop around, right?"

Sherlock rolled his eyes. "Obviously."

"So you know that some people find that kind of thing sexually stimulating."

"Your point, John?"

John sighed. "My point is that you may be one of those people, Sherlock. It's not something you can just decide not to be aroused by - you've got a kink. Big deal - most people do."

"Only slightly over half, depending on how you define the word," Sherlock answered immediately. And then paused. "I never thought about it in any sort of personal sense," he admitted.

John rather thought there might be a lot Sherlock hadn't considered in a personal sense when it came to this particular topic, but most people were strangely sensitive when discussing sex and it was entirely possible Sherlock might feel the same. Not that he reacted normally to other things, but this freak-out was definitely on the odd side even for him.

"Sherlock - do you consider yourself asexual?"

Sherlock tilted his head and frowned. "I don't have enough data to determine that," he finally said.

"Fine. That's fine." John stood. "I can't believe I'm saying this, but - as your doctor - I'm going to recommend that you go watch some porn and analyze your own reaction. Take notes if you think it will help. There's probably nothing medically wrong with you - whatever drug Irene Adler gave you should be completely out of your system by now - but it would definitely be good to make sure everything is working normally. And since you _really_ don't need me here for that, I'm going to go put the groceries away and throw together some dinner. I picked up some chicken salad and some croissants - you hungry enough to eat any?"

Sherlock ignored him, instead reaching for John's laptop. John heaved a sigh and headed back for the kitchen. The pleasant silence lasted less than five minutes before Sherlock was calling him back.

"What is it, Sherlock?"

"Where do I find porn?"

"Are you serious?"

Sherlock shrugged. "Searching online appears to be useless - all the sites with high placement in search rankings want me to pay some ridiculous amount just to look through their archives."

John sighed, leaned over Sherlock's shoulder, and typed in a web address from memory. "There you go - take your pick." The screen filled with dozens of thumbnails of porn videos, most with badly misspelled titles like "HOT MILF GAGGGING 4 CUM" or "DP SEXY ASIAN PUSSY XXX." It wasn't John's normal go-to site for browsing, but it did feature an impressive variety of videos, it was free, and it wouldn't give his laptop a virus.

"Which one should I click on?" Sherlock asked.

John rolled his eyes, then pointed at a relatively tame video he had seen before. "Start with that one. And I can't believe I'm giving you pointers on how to search for porn."

"I've always acknowledged you had a few skillsets I don't," Sherlock said absently. "This appears to be one of them."

"Yeah, thanks. Because I've always wanted to be the porn expert." John hesitated - part of him felt like he really ought to go up to his room, _now_, before this got any stranger. The other part of him was wildly curious to see Sherlock's reaction, especially given the recent revelations.

But so far, Sherlock's only reaction was to glare at the screen with one eyebrow raised. That particular video was rather short and to the point - just an enthusiastic blonde getting pounded into the mattress by her dark-haired partner. They were both fit, and if the blonde had rather improbably large breasts and lips, then oh well. Par for the course when it came to porn, really. Sherlock turned the volume up, filling the flat with an embarrassing combination of wet squelching sounds and breathy moans, then abruptly turned the sound off.

"What is this supposed to accomplish?"

John sucked in a breath, counted to three, and slowly released it again. "People watch porn because they get aroused from watching other people have sex, Sherlock. If this isn't working for you, find something else."

"But they're not having sex - they're acting."

John eyed the rather vigorous activity progressing silently on the screen. "I rather think they're doing both."

"No, the body language is all wrong." Sherlock tapped parts of the image with one long finger. "This woman isn't even aroused - her pupils aren't dilated and her skin isn't flushed, indicating her blood flow level is barely high enough to take into account the gymnastics she's doing with her legs. The man is clearly thinking about something else - someone else, most likely. Ah - see how he avoids looking at her breasts or her waist? He's gay. Why is he filming porn having intercourse with a woman when he's not interested in women, John?"

"I'm sure I have no idea." John licked his lips and tried to will his own arousal away - fake or not, the scene was definitely doing _something_ for him. "There are hundreds and thousands of videos just on that one site, Sherlock - keep looking until you find one where they're not faking."

Sherlock looked dubious. "If you say so."

John rolled his eyes. "Look for something with a riding crop, if you want."


	2. Chapter 2

In retrospect, it was a very bad idea to introduce Sherlock to online pornography. He monopolized John's laptop for the rest of the day and - based on the sounds coming from the living room long after John attempted to go to sleep - overnight as well. John was greeted the next morning by a cheerfully sleep-deprived Sherlock and a dead laptop battery.

"I've been researching all night."

John gave him a side-eye and shuffled into the kitchen to put the kettle on. With any luck, by the time he finished in the loo, the water would be boiling and he'd be that much closer to tea. And he'd have something to do while trying to avoid thinking about Sherlock watching porn as "research."

"I found your browser history interesting, but not as helpful as I'd hoped."

_Christ, he'd_ - but of course he had. Because Sherlock had no boundaries. "I suppose it's too late for me to tell you that's a bit not good, Sherlock. I've given up on trying to keep you from using my laptop, but porn viewing is a rather private activity and I'd like to keep it that way."

"Why is it private?" Sherlock looked honestly confused. "You shared one of your preferred sites with me last night."

"I - hell. Let me go use the loo first and brush my teeth. I'm not awake enough to be having this conversation with you."

John felt much better without morning breath. By the time he re-emerged, the water was boiling and Sherlock was getting out the tea and two cups in what was a blatantly manipulative attempt to encourage John to not be mad.

"Tea, Sherlock? Really?"

Sherlock flashed him an inscrutable look over his shoulder. "I figured you'd be more willing to give your opinion on a few of the videos I found if you had something concrete to do with your hands. Holding your tea works."

"Christ," John grumbled under his breath, not caring that Sherlock probably heard him anyway. And then, louder, "why do you think my opinion would matter?"

"Because you're a doctor, you watch pornography yourself, and you also have a penis so at least the physiology ought to be the same." Sherlock dumped an ungodly amount of sugar into one cup and sloshed a much more reasonable amount of milk into the other. "As you said, you're the expert."

_"That was sarcasm." _But John picked up his tea and followed Sherlock back to the living room, where he had set up (his own, for once, probably because John's was currently charging) laptop at the desk and arranged two chairs for optimal viewing. John perched on the edge of his chair, ready to jump up and go hide in his room if necessary, and waited while Sherlock pulled up the browser and opened a bookmarked link.

"This one got the largest physiological reaction," Sherlock said over the unmistakable moaning and gasping coming from the laptop's speakers. On the screen, a tightly-muscled tattooed man was tied to a padded bench and was being methodically flogged by a smaller but no less fit man with rainbow-colored hair. "I tried to catalogue all the variables - search out videos which included only the sex, only the restraints, only the flogging, only the tattoos, and so forth - but observational studies don't lend themselves well to creating a control group."

John coughed, hiding his expression behind his hand. _Only Sherlock_. "Yeah, this _really _isn't my area, sorry."

"Some of the videos in your search history had similar elements," Sherlock pointed out.

". . . Not the same thing."

"I can't analyze these properly, John. The extreme multicollinearity prevents all but the most cursory of conclusions."

John leaned back and crossed his arms. Sherlock probably wanted him to ask what multi-whatever meant, but he didn't feel like rising to the bait. "And what conclusions are those?" he asked instead.

Sherlock didn't answer right away, instead fiddling with the laptop and bringing up another video - this time of a man being spanked by a tall woman dressed completely in skin-tight leather. "This one elicited a rather elevated response, too," he said. The double-entendre went right over his head, but John had to fight to suppress a completely inappropriate schoolboy giggle.

"So . . . you're into BDSM. Okay."

Sherlock shook his head. "Not the sex - I was able to eliminate that variable on its own; there's a good variety of examples to choose from. It's something else." His cheeks reddened a bit. "Intellectually I know I want to delete whatever is causing my reaction, but . . ."

"But you enjoy it." John adopted his most patient humor-Sherlock-because-he's-missed-something-really-basic voice. "Look, sex feels good. Getting turned on, fantasizing, actual contact with someone else - it's all neurochemical. There's no reason you should feel like you have to hide all that - it's part of being human."

Sherlock shot him a quelling look. "I don't use my body like that."

"Well it's about time you started." John sighed. "Look, odd as it is to suggest, have you tried calling Irene Adler? She's more of an expert on this than I am, and you said she was the one who started this whole line of questioning in the first place. Plus, BDSM is kind of her specialty. You said she's not a threat to the crown, she clearly fancies you, and I bet she'd be on board if you wanted to approach this empirically."

The sudden brightness on Sherlock's face was nearly blinding. "Brilliant, John!" He slammed the lid of the laptop closed, instantly silencing the video. "Here, use my phone. Her number is in the most recently received texts."

John caught the phone on reflex. "Hey now, I wasn't volunteering -"

But Sherlock wasn't listening. "This will be perfect," he muttered to himself, already lost in Sherlock-land. "A chance to craft a controlled experiment, a research aide experienced in the subject matter, and a way to tweak Mycroft's nose at the same time. He'll be furious."

_Yeah, because Mycroft is exactly who I want to be thinking about in this context. _But the only way to make Sherlock to shut up about anything his laser-focus landed on - including porn, apparently - was to allow him to get it out of his system. John dialed.

"Hey handsome," Irene's voice drawled from the other end. "So you do know how to use a phone."

John cleared his throat. "It's John Watson, actually."

Irene hummed. "My greeting still applies."

_Fuck, what do I . . . ? _But Sherlock was staring at him with large, hopeful eyes, and John recovered quickly. "He's making me call - it feels like third form all over again - but Sherlock's discovered a sudden interest in BDSM and wants your help in figuring out what it is."

The line was quiet for several seconds. "Hand him the phone," she said finally. "This isn't the kind of thing you negotiate by passing notes in the hallway."

John dutifully passed the mobile to Sherlock.

"You need my agreement in person?" he grumbled into the phone. A pause. "Yes, exactly. An experiment - I haven't been able to tease out the proper variables." Another pause. "Nearly none - you're not far off." Longer pause. "Yes, that sounds perfect. Yes, he'll come too. No, I know exactly where it is. Tomorrow evening, then."

John stared at his flatmate as Sherlock hung up the phone. "Please tell me you didn't just promise Irene Adler that I'd come with you to a creepy sex dungeon."

"Of course not." Sherlock smiled blandly. "She works out of a two-story house just outside the M25 - rather nice area, actually. Not creepy at all. I suspect because there's enough space between buildings to muffle any suspicious noises. You're free tomorrow at six, right?"


	3. Chapter 3

An assistant met them at the door - no need to punch Sherlock this time to bluff their way in, although John wouldn't have been averse to it for old times' sake - and led them down to the basement. Irene met them at the base of the stairs, wearing a skin-tight leather mini-dress remarkably similar to the one in the video Sherlock found the previous day. She looked amazing in it, which was probably the point. Sherlock barely gave her ensemble a glance, though, running through the bare minimum of a societally acceptable greeting and pointedly looking around while he spoke.

"No need to be so nervous - we've got a tour and quite a bit of talking to get through first," she said with a hint of a smile. John's estimation of her rose a bit - hardly anyone other than Mycroft or himself would have known to interpret Sherlock's rudeness as nerves. (It really was very similar to his signals for anger, frustration, and boredom. Slightly different shape of the mouth, but very close.) Sherlock grumbled, but didn't insist - another point in the "nervousness" category.

"It's a rather short tour, I'm afraid," she continued smoothly. "Loo's through that door there, if either of you boys should need it. It's a working one, floor-to-ceiling tile, lots of room to play, so don't let that surprise you. We'll be staying in the main room today, though. This way." She led them down the short hallway and into a larger room.

Which did have a dungeon-like feel to it, despite being hidden under a comfortably normal house. Not a medieval dungeon - a hospital facility, perhaps, with its white tiled floors and its vague smell of industrial-strength cleaning supplies. The floor probably saw a lot of bodily fluids which needed cleaning. The space wasn't as daunting as John had expected, but it wasn't exactly welcoming either.

The array of torture implements laid out on the tables didn't help. John eyed the assortment and tried not to think about what all of them might be for. Some were easy to identify - the riding crop, the handcuffs, the whip. Others were just twisted bits of metal or leather and were completely unfamiliar. Everything looked scrupulously clean, though, and well-organized. The two long tables were set up within easy reach of the black padded leather bench in the middle of the room. The only other furniture nearby was a flimsy folding table - the kind made for putting your plate on as you watched the telly - with a laptop on it, set near one end of the bench.

"Come on through, then we'll backtrack." Irene led them across the room and through a white door on the other side, which opened into what could politely have been termed an office. It had all the trappings - a heavy oak desk, an executive-style chair, another laptop computer, and a small stack of papers with a fountain pen laid across the top. Modern and classic and tasteful and completely out of place here.

"Quite nice," Sherlock said from the doorway. "Popcorn ceiling is a bit dated, but I'm sure your clients appreciate the effort it took for you to simulate fucking them across their own desks."

His sudden profanity made John wince. Not that John was a stranger to it from other sources, by any means, but it sounded so _odd_ coming out of Sherlock's mouth. More evidence of the nerves Sherlock was trying to hide - he only swore when he was particularly anxious about something. John half expected Irene to pull out a riding crop and whack him a good one right then and there, but she just smiled as if his comment had been a compliment.

"Some of my clients do appreciate a more businesslike setting, it's true." She propped a hip up on the edge of the desk, exposing the long length of her legs and highlighting her dangerously sharp stiletto heels. "I had something a little less exciting, though - I thought John might like to set up here." She leaned diagonally backwards - exposing a bit more of her toned thighs - and hit the power button on the laptop. "I assume you want him to take notes?"

Sherlock nodded. John just stared. There were still times Sherlock could completely throw him for a loop, and acting like it was completely normal to parade through a _fucking BDSM torture room_ and then expecting John to quietly sit at a desk and take notes definitely counted as one of those times.

"Sherlock -"

"No, she's right," Sherlock interrupted. "This really is a perfect setup. I brought printouts of my spreadsheet, but the computer will be easier, even with your hunt-and-poke typing."

"Hunt and _peck_," John growled. "And I still don't know what I'm doing here."

Irene cleared her throat delicately and gestured toward the screen. Which was currently showing a picture of the black padded bench from the other roo - _oh_. John made some rapid mental connections.

"Closed-circuit cameras, as transparent a program as I could get," Irene said. "You're welcome to inspect for hidden recording programs if you wish. The toggles are all here in this row - microphone on or off, speakers on or off, and outgoing and ingoing video feed. John, you'll be able to keep as close an eye on your boyfriend as you like, but you'll also be in control of the feed and of what Sherlock sees and hears from you. I suggest you start with audio and video both on both ways, but you can switch them around later however you like."

It probably should have meant something that the allegation of _boyfriend_ didn't even phase him anymore. John looked around until he saw - _oh_, there was the tiny webcam. "Sherlock, are you sure about this? She's taken blackmail photos once already."

Sherlock made an exasperated noise. "Please, John, I don't have a jealous wife or a political career hanging on my sexual morality. In order to blackmail me, I'd have to be ashamed of my body." He rolled his eyes. "Besides, who on earth would want to see me naked?"

Irene laughed throatily. "At least half the readers of John's blog, for one. Or did you think they were only interested in your cases?"

That made Sherlock blink a few times - recalibrating and assimilating the idea - before dismissing it. "No matter - you'd not have offered if you didn't trust it was secure. Can we start already?"

John gaped. "Sherlock -"

"No," Sherlock snapped. "I came here to learn what the bloody fuck is wrong with my body, and I don't want to dither any longer. The sooner I figure out what the problematic stimuli are, the sooner I can learn how to avoid them." He pulled a small notebook out of his coat pocket. "I took the liberty of cataloging everything I thought might feature in the experiment today - they're alphabetized, and I included a short description for the more esoteric ones. The vertical columns may need some further refinement over the course of the trials, of course, but I marked them with a variety of parameters to start with. The first one is measurable arousal, on a 100-point scale. The second -"

Irene took the notebook from his hand and placed it on the desk next to John, effectively silencing Sherlock's monologue before it had a chance to get started. "John is going to observe, but not like that," she said in a tone which brooked no argument. "I'm going to work my way through the arsenal and you're going to tell him - explicitly, in words - how each experience makes you feel. And if you're very, very good, I might let you revisit a few of your favorites."

John closed his eyes, took a deep breath, and counted to three before opening them again. Living with Sherlock often made him feel a step behind, but tonight felt like he was a whole bloody continent away. "Are you sure?" he asked again.

Sherlock noded tightly - the nervousness still there, but now edged with a manic determination - and indicated for Irene to precede him back out the door. "It'll be fine John," he said over his shoulder. "It's just science."


	4. Chapter 4

Irene left the door between the rooms wide open. John wasn't sure how he felt about that. On the one hand, there was still a part of him that was worried Sherlock was in danger - it was still a possibility (albeit a remote one) that this was an elaborate setup to kidnap, injure, or kill him. Granted, John was the one who had made the call, but some little voice in the back of his brain had learned to shout "DANGER!" whenever Sherlock was doing something impulsive. This definitely counted. Being able to see the whole scene through the open door did help to quiet that little voice a bit.

On the other hand, John wasn't entirely sure he wanted to see _that _much of his flatmate. The webcam was okay - awkward, obviously, but he could always turn off either the sound or the audio if he had to. And it would only show Sherlock's top half anyway. Actually watching the whole thing, though . . .

John shifted the chair to the side a bit, so he could peek out the door. Irene was rolling on elbow-length black gloves - they gave her an interesting dominatrix-slash-operagoer vibe. She flexed her fingers, smiled at Sherlock, and pointed at the bench.

"You. There. Legs toward me." Her voice came both through the doorway and the laptop speakers.

Sherlock just stood there with that superior smirk. "Aren't you going to demand I call you 'Mistress' or something equally inane?"

"Would that turn you on?"

"Not particularly, no."

"Then I won't. Sit on the bench and take off your shirt." She crossed to one of the tables and picked up a coiled length of rope. "I'm merely the lab assistant today, anyway - I'll run you through your paces, but John's the primary investigator for this experiment. He's the one you'll need to tell your results to."

John was pretty sure his brain stopped working for a second or two at the sound of his own name. And at the sight of Sherlock casually prodding at the tiny buttons of his dress shirt with those long fingers of his. John had seen him shirtless before, of course, but this was an entirely different experience and - quite honestly - a bit terrifying. Mostly because the previous times he had seen Sherlock shirtless, he hadn't been anywhere as primed for filthy thoughts as he was right now. And as Sherlock worked the buttons through their loops and shrugged the shirt off farther and farther, those filthy thoughts only intensified.

John wasn't entirely straight. This was no big secret to anyone except Sherlock. Hell, Mycroft had even alluded to one of John's early army affairs (by name) about a week after John and Sherlock moved in together, with the clear implication of "you fuck with my little brother and I'll kill you." (Entirely unspoken, of course, but perfectly clear anyway.) Not an idle threat from Mycroft, either.

Sherlock didn't know because . . . John wasn't sure why, exactly. It just never came up, and then Sherlock was so damned proud of deducing everything else about everyone, and John rather liked having an ace in the hole. It made bearing Sherlock's insults that much easier - every time Sherlock called him an idiot for not realizing the dent in the doorframe meant the victim had spent time in Australia or somesuch half-cocked deduction like that, John could tune out the words and replace them with taunts about how Sherlock couldn't even deduce this one, fairly basic thing about his own fucking flatmate. And then it got to be a while, and there was the whole Moriarty thing, and John couldn't exactly bring it up in conversation _now_. "Oh, by the way, I also sleep with men sometimes. Just so you know."

No, better to keep that all separate from this - whatever-it-was - that he had with Sherlock. Until today, that hadn't been hard: Sherlock showed no interest in sex, romance, or relationships, and John kept his extracurriculars strictly restricted to women Sherlock didn't know. But now Sherlock was shirtless and Irene was tying his wrists together in some highly complicated knot and _fuck_, that shouldn't have made John's cock jump.

"Good?"

Sherlock nodded.

"Out loud and directed at the microphone, so John can hear you. Don't compromise your data."

Sherlock cleared his throat. "She's tying my wrists together with rope - hemp, dyed dark blue. Several loops, to distribute the tension."

Irene tied off the ends of the knot and gave the rope a little jerk, knocking Sherlock off-balance. "Tell him how it feels," she ordered.

"It's fine."

She growled a bit in the back of her throat. "We're going to have to work on your eloquence, I see. On your back, now, face toward the camera."

Sherlock settled his lithe body down onto the leather bench. John's computer now showed from the top of Sherlock's head down to his waist, revealing incredibly pale skin and not nearly enough muscle for Sherlock's height. _He could really stand to put on a good ten pounds_, John's inner doctor pointed out, before being shushed by the part of John which was mostly concerned with appreciating his flatmate's physique on a much more superficial level. He watched through the doorway as Irene drew Sherlock's hands up over his head and - _oh_. There were two distinctive clicks, then she drew back and John could see a pair of handcuffs connecting Sherlock's bound wrists to a D-ring at the base of the bench. Sherlock squirmed a bit, testing his range of mobility. He didn't have much.

"Report, Sherlock."

He swallowed. "Right. Good, better than I was expecting. Limited freedom of motion is a positive, and I think the use of actual handcuffs is having a positive effect as well. Mark that down in the third column for -"

"That's enough," Irene interrupted. "John, ignore the columns - just write your notes freehand and Sherlock can interpret them later."

Sherlock's head snapped up. "Quantifiable data is essential! Analysis becomes almost impossible if-"

John's eyes were on the laptop screen, not the doorway, so he missed seeing whatever it was that made Sherlock yelp suddenly and completely lose his train of thought. He peeked out just in time to see Irene swing the wooden paddle back and give Sherlock a solid whack on his other hip. Sherlock's trousers surely cushioned the blow somewhat, but the man had almost no body fat for padding - that would have _hurt_.

"Report."

"I, ah." He cleared his throat. "Wooden paddle isn't something I particularly feel the need to repeat."

Irene turned to look directly at John through the open doorway and raised one eyebrow. John didn't have to guess to know what she was expecting him to ask -

"Break it down for me, Sherlock," he said into the laptop's microphone. "What parts didn't you like? The pain? The hip? The paddle itself?" Only a tiny tremble in his voice betrayed him. Sherlock's eyes met his through the camera and _shit, he can watch me too, can't he?_ John hesitated a moment, then clicked the button to turn off the outgoing video feed. He was perfectly happy to watch Sherlock - so far, anyway - but letting Sherlock watch him, deduce him, felt like a bit too much.

But Sherlock didn't seem to think there was anything uncomfortable about John's position at all, and he barely blinked when the picture disappeared from his screen. He actually looked like he was considering John's question carefully. "I'm fairly sure I didn't like it on my hip," he said after several seconds. "Impact and sensation play in other forms are probably fine, but I lack the data to hypothesize about the paddle in comparison to other instruments."

Irene nodded. "Fair enough. John, I assume you can hear me okay?"

"I'm twenty feet away and the door is open. Yes, I can hear you just fine."

"What would you like me to focus on next? Working through more impact play, or bondage? Or is there a particular area of Sherlock's body you want me to concentrate on?"

_Why the fuck are you asking me?_ He didn't say it out loud - mostly because he wasn't sure if he'd like the answer. But a good number of those toys would presumably involve her taking Sherlock's trousers and pants off, and John definitely wasn't ready for that yet. "Chest," he finally said. "Whatever you've got."

She barely had to glance down at her table of supplies. "Nipple clamps, ice, wax, although that will take a few minutes to heat up. Suction pump for nipple enlargement, if you'd like to see him really writhe."

Yeah, he would have had to have been blind not to notice the way Sherlock's eyes dilated a bit at that. "That last one," John said. "Maybe work up to the others?"

Irene didn't reply, just rifled through the objects on the table and came up with two black bulbous shapes John hadn't recognized at closer range. She lined them up over Sherlock's nipples without preamble and squeezed both bulbs. Sherlock's eyes went wide and he sucked in a deep breath.

"Talk to me," John prompted through the computer. It was a bit less intimidating to be here, doing this, when Sherlock was making that shocked expression - a clear signifier he wasn't entirely in control of what was going on, either, and he knew it. _That makes two of us._

Sherlock's eyebrows drew together, and his mouth opened, but no sound came out.

It was - to be honest - amazingly hot. Sherlock was so rarely without words, and seeing it in this context was so far beyond anything John might have ever imagined . . . _Not that I've been imagining this_, he reminded himself. But it was hard not to imagine now. John had to reach down and adjust himself through his trousers.

He decided to start slow. "Hurts?"

Sherlock nodded once.

"Good hurt or bad hurt?"

"Ah . . . good hurt?" He panted out another breath. "Excruciatingly sensitive, and will get more so the longer the suction is applied. It . . ." He licked his lips. "Christ."

_So those went in the "yes" column_. John wrote a few words to remind himself - not likely he was going to forget a single second of this, but still - and bent back toward the microphone. "Might as well get the wax heating, then."

Sherlock's breathing got faster. Interesting.

"Is that okay?" John asked.

Sherlock swallowed and nodded again.

John suddenly realized - "Is there anything you know for sure is not okay? Something you want to tell us before we go any further?"

"I . . . don't know." He squirmed, shifting his shoulders over the leather of the bench. "I lack the experience to know precisely what the expected boundaries for this sort of thing are."

_Ah. Trust Sherlock to try to analyze his reactions in the context of wider statistics while in the middle of a scene . . ._ "Don't worry about what's expected," John said. "This is about your body, no one else's. And like I told you back at the flat - there's no reason to be ashamed of how you're wired. It's just how it is."

"What about you?" Sherlock was looking directly at the camera, even though John knew the video feed was only one-way at this point. "How much of this are you wired for?"

_Christ_. John ran a hand through his hair. "Not really that simple, Sherlock."

"Why not?"

"Because every partner is different." John released the breath he hadn't known he'd been holding. "If the person I'm with particularly loves something, I usually can find myself getting turned on by watching them enjoy it. Even if it's something I wouldn't want done to myself. And if there's something they really _don't_ like, I don't find it sexy to push them into it. It's just . . . complicated."

Sherlock bit his lower lip and froze for a long moment. "Was - was your lack of gendered pronouns deliberate?"

_Shit_. Well this was as good a time as any to come clean, right? "I wondered when you'd reach that conclusion," he admitted. "Yeah, it's not just been women."

The shocked look on Sherlock's face was priceless. The idea of John being bisexual seemed to have put him offline for several seconds, until Irene's hands appeared in the frame of the video, pinching and removing the suction bulbs. Sherlock moaned softly as they came off. His nipples stood out vividly against his pale chest - they were dark red, nearly purple with engorged blood, and they looked painfully huge. John couldn't resist reaching out and stroking the screen, running his fingertip over the image. Fuck being an impartial observer - Sherlock looked incredible. John let his other hand drift down to his crotch and just rest there, a warm weight over his erection.

"Wax is ready." Irene held the jar candle low over Sherlock's abdomen - so John could watch, presumably - and tilted it. The red wax spilled out in a thin stream, pooling in the hollow of Sherlock's sternum.

_"Bloody -" _Sherlock closed his eyes and panted as Irene let more wax drip on his ribcage, then on his pectoral - not on his nipple, not quite, but close enough that John could feel a sympathetic tingling in his own body. When Sherlock opened his eyes again, they were wide and wild.

"Tell me," John commanded.

"I - fuck."

"The experiment, Sherlock. I need consistent data. Real words."

Sherlock licked his lips. "Yes. This is - this is a yes. _Fuck._"

John grinned and made a note. The camera only went down to Sherlock's navel, but he'd bet a good sum of money Sherlock's pants were feeling uncomfortably tight by now. Just like his own. He squeezed his cock gently through the fabric, then massaged himself without taking his eyes off the scene in front of him. Thinking would be too much - thinking about this would make him realize how fucked up it was to be stroking himself off while watching his flatmate completely lose it. As long as he didn't think, though, it was okay, was fucking amazing to see . . .

"Do it," John said aloud, and Irene shifted the candle that last inch to dribble a large drop directly on Sherlock's sensitized nipple.

Sherlock screamed. There was no other word for it. The muscles in his shoulders bunched and shifted as he pulled at his restraints, but they held fast - all he could do was squirm and swear and roll his head back and forth against the padded bench. It was quite literally the sexiest thing John had ever seen, and that was saying a lot. John felt his own breath catch in his throat and his cock give a predictable lurch. Irene brought the candle to Sherlock's other nipple and repeated the process, with similar results.

"Tell him how it feels, Sherlock," Irene prompted. "Tell him what you want him to do."

Sherlock groaned and broke into a string of profanity in what John was pretty sure was French, based on the few words he recognized. "So bloody hard now, John," he slurred, his normally-precise diction gone. "I want - I want -"

"You want your trousers unbuttoned?" she said. "Relieve some of the pressure?"

"God, yes."

"You heard him, John. I promised I'm not touching today - it's up to you."

John's mouth fell open. "Sherlock -"

"Tell him." Irene's hand came back, this time with a stainless steel implement John vaguely associated with medical school history books - scalpel-sized stick with a wheel at the end, rimmed with little spikes. _Wartenberg wheel_, his subconscious provided. _Not used to test reflexes anymore, but still popular in the BDSM community. _Right, so that would be why it stuck with him -

Irene zipped the wheel quickly up Sherlock's abdomen, from navel to breastbone, avoiding the now-cooling wax. The tiny pinpricks weren't enough to draw blood, but they must have hurt like the devil. Sherlock arched up off the bench again.

"Tell him what you want him to do to your cock," Irene repeated, running the wheel more slowly in looping circles over Sherlock's pectorals. He writhed underneath her.

"I want -"

John held his breath.

Sherlock swallowed hard when Irene pressed the wheel down a bit more firmly, goading him. "I want you to come unzip my trousers and take out my cock, John. I think I want to see what it feels like to ejaculate. To come."

Irene's hands faltered - he had surprised her, then. John let go of his cock and gripped the arms of his chair tightly. "Sherlock -"

"Please, John. Have mercy on me."

Recent words rang in John's brain. _"I would have you right here until you begged for mercy. Twice." "I've never begged for mercy in my life." "Twice." _God, Sherlock begging -

He was moving before he even realized it. _Fuck, I've never been able to tell him no before, no reason to expect I could start doing so now . . ._

Sherlock's head snapped upright when John stepped into the room, but his eyes were still wild and unfocused. "Please," he whispered.

And that was all there was to it. John took a deep breath and went to stand on the other side of the bench, across from where Irene was still trailing that needle-studded toy slowly over Sherlock's chest and abdomen. Sherlock's eyes followed as John reached down with trembling hands and slipped the button on Sherlock's trousers free of its mooring, then dragged the zipper downward. Even though the trousers, he could feel the pressure of Sherlock's erection pushing against the fabric. With the trousers loosened, Sherlock's cock tented obscenely inside his pants.

"You want them all the way off?" John asked quietly.

Sherlock nodded immediately, biting his lower lip so hard it drew a bright bead of blood. "Everything off," he whispered. "Need to feel . . ."

John slid off Sherlock's shoes and socks first, then dragged his trousers down and left them crumpled in a heap on the floor. The pants followed soon afterward. And then Sherlock was completely nude, cock thick and flushed and gorgeous and _fuck _he looked so incredible. John's palms literally itched with the need to touch him.

But Irene caught his eye, and John refrained. She reached down under the bench, did something, and came away with a rectangular section of black leather in her hand.

"Roll over, flat on your stomach," she commanded. "John can help you if you need it."

Between the two of them, John was able to get Sherlock flipped over without pulling too much on his arms. In the process, he saw what Irene had done - the bench now had a strategically-placed hole cut in the center, allowing Sherlock's cock and bollocks to dangle through without being crushed by his body weight. And allowing easy access, if anyone were inclined to do so. John looked back up at Irene, but she had her back to him, selecting something off the table. Something long and -

_Ah_. The riding crop. By the sudden quickening of Sherlock's breathing, John could tell Sherlock had seen it too.

"Face John."

Sherlock turned his head to the side, eyes locked on John, looking absolutely wrecked and desperate. John hesitated only a moment, then sank down to sit on his heels so his face was just inches from Sherlock's. Somewhere in the back of his mind he knew this was new, was blundering even further over the "just flatmates" line, but Sherlock needed him right now and fuck if he could ever say no. Not like that. John's fingers rose of their own accord to comb through Sherlock's thick curls, and it felt glorious.

The first blow, when it fell, made them both jump. The _crack _of leather against skin hung in the air a long moment before disappearing. Irene followed it up with a second swat, on Sherlock's other cheek, then a long caress down the length of Sherlock's spine.

"That's it - just watch your boyfriend. Talk to him. Tell him how you feel." _Crack_.

Sherlock shivered. "John . . ."

Oh God, the sound of his name on Sherlock's lips . . . John had to close his eyes and hold his breath to keep from just dropping his own trousers and shoving his cock into that gorgeous mouth. This wasn't about him, it was about Sherlock, and what Sherlock needed right now was a connection. John carded his fingers through Sherlock's hair again, and Sherlock shivered - this time with pleasure.

"She's right," John said quietly. "You wanted data - tell me how this is making you feel."

"So good," Sherlock mumbled. _Crack crack_ - on the backs of his thighs, in quick succession. "A bit floaty - it hurts, but I can't be arsed to care."

"That would be the endorphins flooding through you. A natural high."

Sherlock moaned. "If I had -" - _crack _- "- known about this, I might not have needed cocaine."

John smiled a bit at that. "You've really never had an orgasm before?"

"Mmmm. Not while awake. I want -"

_Crack crack crack._

"Yes?"

"Want you." He shivered as Irene trailed the crop down his leg, over the soles of his bare feet, and back up his other side. "Want it to be with you."

"You want the first time you come to be with me?"

"Mmmmm." He closed his eyes, drifting under the alternating series of caresses and blows.

They sat in silence for a full minute, the only sounds being the occasional _crack _of the riding crop and the resulting noises torn from Sherlock's throat. Irene was being careful, John noticed - well, not surprising, since she must have had a lot of practice. But the doctor in him approved of how each blow was carefully placed so there was no chance of actual tissue damage. Bruises, yes, but nothing permanent. She met his eyes and her lips twitched upward into a tiny smile.

"Sherlock," she said quietly.

Sherlock opened his eyes.

"Look at John. Look at what seeing you like this does to him."

John's throat constricted, but he held perfectly still as he felt Sherlock study him. And eventually regained enough brain function to really _look_. Sherlock licked his lips - probably still tasting the blood from where he had bitten clean through his bottom lip - and the sight made John's cock jump. Sherlock noticed.

"Look at how aroused he is - gorgeous blush in those cheeks, eyes wide. So turned on. He wants to let this be all about you, but it's not, is it? You'd like to see him come."

Sherlock nodded, his eyes flicking back up to John's.

"Beg him. Convince him to pull himself out of those cumbersome trousers and work himself through the rest of the way."

John's mouth dropped open. _No,_ his brain immediately said. _Too much, too -_

"I want to see you," Sherlock whispered, and John's brain went silent. Sherlock shifted his hips a fraction, thrusting against the bench even though John knew he wasn't getting any friction where he wanted it. "Please, John."

"I -"

_"Please."_ Sherlock's eyes were haunted, now. Desperate. "I want you to touch yourself. Touch me. Use my mouth to bring yourself off. Come on my face, in my hair. I want your scent in my nose and your taste on my tongue. God, John, _I need you_."

They could have suddenly been in front of a million people, in front of Harry and Mycroft and Lestrade and the queen herself, and it wouldn't have been enough to stop John from quietly reaching down and unbuttoning his trousers. Drawing down the zipper and his boring gray Y-fronts and pulling himself out. He was already so hard, so gloriously hard -

Sherlock's eyes widened at the sight, which of course only made John harder. He suddenly wondered whether Sherlock had ever tried to imagine him like this, had ever spared any space in that great mind palace of his for what John might look like without his pants. He sensed Sherlock was surprised, so maybe the answer was no - but then again, it's possible Sherlock's reaction was just because this was so terrifyingly _real_.

Sherlock's tongue darted out to trace over his bottom lip, and suddenly John's resistance was gone. He wrapped his palm around himself, sliding a few strokes dry, just adjusting to the feeling of Sherlock watching him so intently. It felt electric. Sherlock's lips parted, as if he was imagining the taste -

John extended his hand, palm-out, close enough he could feel Sherlock's breath on his skin. "Lick," he commanded. "Get me nice and wet."

Sherlock did. His tongue traced a few lines on John's palm, then darted out again to lave a rough line up the center. John sucked in a breath and tried not to shudder. Sherlock noticed, of course, and redoubled his efforts to make John squirm. By the time he drew his head back, John's palm was dripping with Sherlock's saliva and John was harder than he'd ever been in his life.

And the touch of his wet palm on his warm cock was absolute heaven. John closed his eyes and groaned, only belatedly realizing Sherlock was groaning right alongside him. He pumped slowly, glorying in the sensation. When he opened his eyes, Sherlock's intense gaze was focused entirely on his cock and his mouth was hanging open.

"Please," Sherlock whispered. "Let me -"

John worked his way to standing, on wobbly legs, and tilted himself forward so his pelvis was just barely resting on the edge of the bench. Sherlock didn't have a lot of room to maneuver, but he managed to work his mouth over the tip of John's cock and slide about half of it inside.

_"Fuck," _John breathed. Sherlock moaned throatily around him, the vibrations nearly bringing him over the edge already. But John didn't want that yet, didn't want to come in Sherlock's mouth -

He barely pulled out in time. Sherlock's tongue caught him by surprise, the tightening in his balls sweeping over him so fast he literally had to shove himself away from the bench to get his cock out of Sherlock's mouth as he came. John watched, as if from a distance, while the white spurts splattered across Sherlock's lips, his cheekbone, in his hair. He may have yelled something when he came, but he didn't know for sure. The look on Sherlock's face, though . . . he looked thoroughly debauched, absolutely wrecked, and painfully desperate. John took a shaky step back and collapsed back onto the floor.

Irene jerked her head to catch his eye, then nodded toward the cutout in the bench. _Right. _There was no longer a question about it - John was going to jerk Sherlock off, and Sherlock was going to have his first orgasm, and this would be simultaneously the most surreal and the most fantastic day of John's life.

Sherlock nearly shouted the moment John's fingers found him. John couldn't see what he was doing, but he used Sherlock's reactions to guide him - the way Sherlock jerked when he encircled his girth, the way he groaned when John twisted the foreskin away from the glans _just so_ and pulled -

Irene caught his gaze again and positioned herself at Sherlock's feet. John watched out of the corner of his eye as she drew back the riding crop, let it swing -

He tugged at the same moment the crop landed across Sherlock's arches. Sherlock _screamed _and came. His whole body shuddered for several seconds, John felt a warm stickiness coat his fingers, then Sherlock went boneless and Irene was discreetly headed for the door to the hallway.

_I'll give you two a moment_, she mouthed, and then she was gone.

John swallowed thickly. _That just happened. That really just happened_. He was still feeling a bit floaty himself, and he could only imagine how Sherlock felt . . . John quickly untied the slipknot holding Irene's complex rope creation over Sherlock's wrists, and the navy loops fell away. He reached up and tugged at Sherlock's hips. It took some force, but he managed to pull Sherlock sideways off the bench to lie curled in his lap on the floor.

Sherlock looked up at him and blinked. "That was . . ."

"I know," John whispered against his ear. "I know."

"Are orgasms like that every time?"

John hid his smile. Not successfully enough, judging by Sherlock's expression. "Only the good ones," he said. "It may take repeated experimental trials to acquire all the data."

Sherlock murmured and buried his face in John's good shoulder. "You'd be willing to - with me?"

_Always_. "Maybe not here, but yeah." John rubbed small, soothing circles against Sherlock's shoulderblades. "I think we can work out where to go from here ourselves, don't you?"

"I can't believe I -" He wriggled a bit and looked up so he could see John's face. "I can't believe I didn't know about this. I'm sure I wouldn't have deleted it if I had known how . . ." He broke off and frowned.

"How it felt to be loved?"

Sherlock nodded, a serious expression on his face. "And to be in love with someone. Is that - is that okay?"

John inclined his head to press a soft kiss onto a clean section of Sherlock's forehead. "That sounds good."

"Good."

And they sat there together, entwined on the floor, until it became clear Irene wasn't coming back.

She did, however, leave the riding crop in a fancy gift box just inside the front door, with a note: "Thank you for the lovely time. Enjoy."

They did.


End file.
